Mag Deficiency?!

Two outdoor girls in second week of flower. Was giving cal mag supplement but stopped because it has nitrogen in it and was lowering nitrogen upping phosphorus. On fox farm trio with the soluble trio (currently on beastie bloomz).

Bigger of the two girls are showing what looks to be a mag deficiency or the begin of it. I would think being outdoor and well water (6.5ph from tap) that they are getting plenty of mag. Thinking soil ph is off. Not sure how to measure the soil ph properly since they are in raised boxes on the ground.

Thinking of a flush to reset ph but not sure what to do without a proper ph reading… if this is indeed mag deficiency. Red stems were here much longer then the yellowing…

Definitely magnesium. I would at least feed epsom salt. No nitrogen.

Foliar spray? Or via soil? Can I foliar spray them with buds?

You could try spraying, but I’ve never foliar sprayed. I always add it to the roots. Less chance of burning the leaves in the sun/light. The leaves that are showing deficient, won’t recover.

Ok. I’m worried it’s from a few things. Probably not ph in soil because I’ve adjusted everything that goes in. I live very far north so it is getting cold. Thinking the cold may be the reason for the inability to uptake the mg. Also- I just tried pushing my nute feeding further then I have been, so maybe lockout due to p. I have plans on flushing them and then giving them a dose of epsom each to try and rectify. Will also cut back my feed back to the once a week I had been doing. Thanks for your help- let me know if you think I should do anything differently then mentioned above. Going to plastic these girls in to keep them warm and get them through until harvest- maybe that will help.

Plastic is a very strong suggestion. Everything else sounds good.